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Surgery Gone Wrong: The Importance of Medical Malpractice Expert Witness Testimony on Causation


In a medical malpractice case, the importance of proving causation cannot be overstated. To establish causation, almost all medical malpractice cases require medical expert witness testimony to help juries understand the connection between an alleged breach of the standard of care and the injuries suffered.

The recent defeat of a plaintiff’s malpractice claim in the Arizona case of Sampson v. Surgery Center of Peoria, LLC, et al. serves as a chilling reminder of how equivocation from an expert witness can sound the death knell for your medical malpractice case.

Sampson v. Surgery Center of Peoria

In Sampson the Arizona Supreme Court considered a claim brought by the parents of a four-year-old boy who went through outpatient surgery for a routine tonsillectomy and adenoidectomy at Surgery Center. This is a standard procedure that requires the use of general anesthesia. The doctor remained with the patient for 30 minutes after the surgery. He was released from post-operative care an hour later, taken home by his mother, and put to bed. Two hours later he was discovered not breathing. The cause of the child’s death was disputed: one expert believed it was caused by strep while another believed that the after-effects of surgery and anesthesia caused the child’s airways to become obstructed and prevented him from awakening when he struggled to breathe.

The plaintiffs’ expert medical malpractice witness opined that Surgery Center should not have released the child for at least three hours, especially since he had a history of sleep apnea. However, with respect to causation, the expert stated only that proper observation “could have” allowed Surgery Center personnel to revive the child and save his life.

The Arizona Supreme Court determined that this medical expert opinion was insufficient to establish causation. It explained, “In a case where the standard of care or the cause of death is disputed on a matter requiring medical knowledge to resolve, it is difficult, if not impossible to imagine a situation where lay jurors, untrained in medicine or medical procedure, could properly determine liability absent expert guidance.”  And in this case, where the experts didn’t even agree on the cause of death, the Arizona Supreme Court considered it “unrealistic” to expect a jury to be able to “infer causation even where the expert could not, or would not, state . . . that the Surgery Center’s deficiency in adhering to the standard of care was the probable proximate cause of the death.”

In other words, the medical expert witness is there to connect the dots between the medical provider’s failure to uphold the expected standard of care and the patient’s injury or death. And woe be to the lawyer whose medical expert fails in that task.

Importance of the Medical Malpractice Expert Witness

Medical malpractice experts too often have the power to make or break your case. Their testimony is a crucial part of any malpractice litigation strategy, and it is important to choose your medical expert carefully.

As with any witness, medical or non-medical, strong expert testimony can provide important credibility to your arguments and strengthen your case. Choosing a qualified medical malpractice expert witness who will hold up even during harsh cross-examination is invaluable. Most importantly, you need to be sure that your expert witness won’t equivocate when it comes to their essential opinion regarding causation.

The medical malpractice expert witness is a part of the plaintiff’s team and a powerful tool for the attorney to establish causation and other elements of the case. A high-quality medical expert provides value at every stage throughout litigation, not just trial. Medical expert witness findings can aid attorneys in evaluating the strength of a case. They can also make a clear distinction between medical malpractice and medical maloccurrence, which is crucial prior to filing a medical malpractice lawsuit.

Selecting an Appropriate Medical Expert for Surgery Malpractice

It is the duty of surgeons who testify as medical malpractice experts on behalf of defendants, the government, or plaintiffs to do so solely in accordance with their judgment on the merits of the case. They must limit testimony to their sphere of medical expertise and must be prepared adequately.

Selecting the appropriate medical expert witness in any given case depends in part on the facts of the case and procedure to ensure proper qualification. However, in light of these additional requirements, expert selection must also take into consideration the requirements for the jurisdiction where the case will be filed.

AMFS has over 6,000 medical malpractice expert witnesses across more than 212+ medical specialty fields. We commit to pairing you with high-quality experts uniquely appropriate for your specific case in your specific jurisdiction. AMFS focuses exclusively on the medical and health care fields and provides additional resources to assist throughout the medical malpractice litigation process. The AMFS network of qualified surgeons and other expert medical consultants is here to help you and your client determine the best strategy to move forward with a clear understanding of how to establish causation and the other elements of your claim.


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